#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])

{

    int up1,down1,up2,down2;

    do{

        printf("Enter two fractions seperated by a plus sign:");

        scanf("%d/%d+%d/%d",&up1,&down1,&up2,&down2);

        int down3=down1*down2;

        int up3=up1*down2+up2*down1;

        int small=(up3<down3)?up3:down3;

        int gcd;

        for(;small>;small--){

            if(up3%small== && down3%small==)

            {

                gcd=small;

                break;

            }

        }

        printf("The sum is %d/%d\n",up3/gcd,down3/gcd);

    }while(up1!=);

    return ;

}

Enter two fractions seperated by a plus sign:/+/

The sum is /

Enter two fractions seperated by a plus sign:/+/

The sum is /

Enter two fractions seperated by a plus sign:/+/

The sum is /

Enter two fractions seperated by a plus sign:/+/

The sum is /

Enter two fractions seperated by a plus sign:/+/

The sum is /